Sunan Abi Dawud

Narrated Yusayrah, mother of Yasir: The Prophet (ﷺ) commanded them (the women emigrants) to be regular (in remembering Allah by saying): ""Allah is most great""; ""Glory be to the King, the Holy""; ""there is no god but Allah""; and that they should count them on fingers, for they (the fingers) will be questioned and asked to speak